Senior SWE

### About the Role This is a rare opportunity to own the SDK layer of a widely adopted open-source AI engineering platform — the kind of tooling that sits at the very first touchpoint developers have with the product. The SDKs you build ship to **millions of downloads per month**, running in production environments ranging from serverless functions to long-running agent loops. When you ship, thousands of developers benefit the same day. The bar is high: zero-failure reliability, minimal CPU and memory overhead, and idiomatic developer experience across Python and TypeScript. You'll be the person who sets that bar and upholds it. ### What You'll Do * **Own Python and TypeScript SDKs end-to-end** — reliability, performance, and developer experience. You'll drive major version rewrites and architectural improvements, including work on OpenTelemetry-based tracing. * **Design APIs developers love** — every detail of naming, parameter structure, breaking change communication, and documentation is yours to shape. * **Integrate with the AI ecosystem** — build and maintain integrations with LLM frameworks, model providers, and agent runtimes; keep pace with a fast-moving ecosystem. * **Maintain and grow open-source community health** — triage GitHub issues, review pull requests, engage with contributors, and communicate clearly on public channels. * **Drive performance** — profile, benchmark, and optimize SDK footprint across latency, memory, and throughput dimensions. * **Own the release lifecycle** — versioning strategy, changelog communication, compatibility testing, and CI/CD automation for library releases. * **Collaborate cross-functionally** — work closely with product and data teams across EU timezones in a small, high-trust distributed team. ### What We're Looking For **Required:** * 5+ years of professional software engineering experience, with at least 2 years building or maintaining SDKs or client libraries * Proven track record designing, implementing, and maintaining production-grade SDKs — including API design, versioning, packaging, and release management * Experience optimizing library/SDK performance (profiling, reducing latency and memory usage, improving throughput) * Hands-on experience with observability, tracing, metrics, or monitoring systems — designing or instrumenting telemetry for debugging and analytics * Proficiency in at least one SDK-relevant language (Python, TypeScript/JavaScript, Go, or Java) with ability to write idiomatic, production-quality code * Active open-source experience: handling GitHub issues, PR reviews, and community interactions * Strong written and verbal communication skills; comfortable writing documentation and engaging publicly (GitHub, social/developer channels) * Experience with automated testing and CI/CD pipelines for libraries (unit/integration testing, release automation, compatibility testing) * Ability to work effectively in small, distributed EU-timezone teams * **Legal authorization to work in the EU — no visa sponsorship available** **Nice to Have:** * Familiarity with analytics or large-scale telemetry systems (e.g., OLAP/columnar analytics databases) * Bachelor's degree in Computer Science, Engineering, or equivalent practical experience ### Location This is a **hybrid remote role** based in Europe. You'll work remotely most of the time, with the expectation of being on-site in **Berlin, Germany** approximately one week per month. The team spans Germany, Austria, Switzerland, the Netherlands, France, Sweden, the UK, Spain, and Poland. ### Compensation & Benefits * **Salary:** $90,000 – $160,000 USD annually (or local equivalent), depending on experience and location * Opportunity to have meaningful impact on a high-adoption, widely used open-source project in the AI/ML space * Work within a small, senior engineering team backed by top-tier investors including Y Combinator Find more [English Speaking Jobs in Germany](https://www.arbeitnow.com/english-speaking-jobs) on Arbeitnow